This invention relates to film viewing devices and more particularly to a portable viewer for viewing microfilm stored in a cassette.
With an increased number of information retrieval systems, there are presently available various types of information storage mediums. In many cases microfiche cards are used for storing information while other situations required use of storage on microfilm. With either type of storage medium a viewer is needed to permit easy access to the information stored on the medium.
Large viewing devices for such storage medium are readily available. Such devices are often utilized independently or in conjunction with other electronic equipment such as computerized input terminals and the like. However, often individual use of a viewer is needed and the expensive complex equipment is superfluous. It is rather important to have a portable hand held viewer to view such storage medium.
There has already been made available various microfiche viewers which can be hand held and utilized to read the information stored on the microfiche cards. Likewise various types of portable viewers for microfilm have also been made available. For example, U.S. Pat. No. 3,280,491 issued Oct. 25, 1966 to the present inventor describes a simplified microfilm viewer which operates on microfilm from a spool to spool arrangement and utilizing a windup spring for providing rotary motion through a gear train to a selective one of the spools to drive the film in a forward or reverse direction. U.S. Pat. No. 3,543,424 issued Dec. 1, 1970 to the present inventor describes another type of portable microfilm viewer where the film is contained in a cassette and has a motor pivoted in a housing. The motor can be selectively moved between two gears which are respectively associated with the two spools in the cassette. A third patent U.S. Pat. No. 3,589,043 issued June 29, 1971, to the present inventor describes a further type of portable microfilm viewer having film in a cassette with a spindle having a one way clutch mechanism connected to it. A drive wheel operates to respectively move the film between the spools in a forward or reverse direction.
While each of the aforementioned portable viewers for microfilm, as well as others, have useful and novel features each of them have some drawbacks which prevent them from becoming a widely used viewer. In some cases, the absence of a cassette may cause damage to the film which may jam the entire operation or mar the film. In other cases, the necessity of pivotally shifting the motor within the housing causes noise vibration and possible damage to the motor itself. In other situations, the complexity of the gearing or clutching mechanism increases the cost of both the cassette and the viewer making it impractical for regular individual use.
While a simple inexpensive microfiche viewer can be utilized for many applications, there is nevertheless needed a simple inexpensive microfilm viewer which can be efficient, small, easily operated, and durable. The use of microfilm provides a simple method of storing and accessing a mass amount of information. For example, on a single cassette even more than 2,000 frames can be provided. On a single cassette can be included diagrams and blueprints for circuits, dictionaries, educational lessons, and other types of information.
A simple portable microfilm viewer could be utilized for various purposes. By way of example, airlines could provide their passengers with such a viewer and accompanying cassettes enabling them to pre-tour their destination on flight or before their trip. Included could be information about sites to see, restaurants, and museums. Students could utilize such a viewer for learning various subjects at home or reviewing them in school. Law enforcement individuals could carry such a device with cassettes containing information involving license plates, mug shots, or other vital statistics. Public utilities could provide their servicemen with these devices having all service manuals and blueprints placed in cassette form. Additionally, drivers could utilize them with interchangeable cassettes having addresses and street maps for various cities.
It is therefore evident that providing a successful portable microfilm viewer has almost unlimited use. However, heretofore, the available microfilm viewers have not been able to provide the needed functions necessary to satisfy the requirements for such a successful viewer.